Rhodochrosite

Peter,there are a few more small bugs in the book.. so there is no cinnabar from Camberg .. it is just an old misread label from Lemberg. But i think this doesn´t make the book less attractive and i believe it to be a very good contribution on rhineland-palatinate mineralogy. If there will be a second edition i am sure that the folks at NHM will correct the issues.

A question: i am just working on the Oberneisen text for the article and i have plenty of literature (quite old but i think sufficient) on geology .. but nothing up to now on the mine´s history .. do you have any?

Furthermore i am trying to get the permission to use old site pictures ... if any of you have contacts to people who have historic photographs of Siegerland mines, please try to persuade them to grant us permission to use .. i will try my best also.

BTW i have been at Battenberg recently ... the "Blitzröhren" limonite occurrence, got some nice pictures which i will post if i find the time. Maybe the baryte site will be rediscovered also in the future.

Jesrocks,What about the Champion mine? Does it produce good rhodochrosite specimens? Can you provide a picture of two or three good specimens? How many were produced. What does the best one look like? When were they produced?

Check Mindat pics for a picture of rhodochrosite from Champion mine. These are fairly like the rodos from the Sunnyside mine in colorado, last summer I collected there ( I know the people that own it and they didnt even know that rhodochrosite was even found there) and found one of the best specimens that has ever come out of it

Jesserocks,First off we would like to know who we are talking to. Second, there appear to be no images in Mindat of any specimens from the Champion mine. Which Champion mine are you talking about? Its in Colorado, right?

Do you want to know how to upload an image to mindat? Before you can do that you will have to register with your real name. Then you will need to read the part of the mindat manual about uploading pictures. Then you will need to request permission to upload them and then you will be raised to a level one membership. The reason for this is that we don't want just everyone to be able to upload stuff to mindat. We have had way too many problems. When we know who you are, then if there are any questions about what you uploaded then we can get back to you about it and ask questions.

This is all part of a process that will probably get tougher as we go along. The reason for this is there are already too many errors in the locality strings on mindat and in the captions that have been uploaded in the past and we are probably going to try and make a serious effort to try and clean up the mess.

If a locality is not on mindat, we will want to add it to the database, but we are becoming more protective of our locality data than the images that mindat members upload because it is easier to screw them up than it is the photo uploads. We now require a reference, usually a literature reference to the locality before we will accept it and GPS degree minuite second if we can get it.

Rock,yesterday nite is talked to the RWTH Aachen institute of mineralogy custos, Dr. Annemarie Wiechowski. It will be possible to visit her in early summer and to take pictures of the very good rhodochrosites from Wolf mine which are in the institute collection. ... so this will last a bit but may produce nice results. Description of Wolf and Oberneisen mine are "under construction" still.

Roger,There is no particular rush. These articles are never really finished. Like Mindat. Always new data to enter and corrections to be made. When you can get the pictures, they will I'm sure be welcome. The whole rhodochrosite article her is shortly due for face lift.

Sorry, Im new to mindat only 13 and I didnt know anything. Try looking up Champion mine, Hindsdale county, Colorado I know they have a photo of one because I have seen it, sorry I wont make any more posts.

Jessie,OK, I have found it. It is not a great specimen, but I think probably good enough to go in the article. It is sort of marginal, but it makes the cut, at least my cut. Each author who writes these articles will have somewhat different standards though if you can make a good case for inclusion we will usually bend and stick it in. You go ahead and do all the posts you want and ask all the questions you want. I would suggest however that before you do a post that you Google around a bit and see if you can find the answer on your own and then if you can't find out what you want to know or what you have found sounds a little fishy or you still don't quite understand what they are telling you, then hop on board and ask questions. Keep in mind that you are talking to the world here through a website out of the UK and that you are talking to some of the smartest and some of the dumbest people there are. You don't need to worry about the dumb ones, you just don't want to embarrass yourself in front of the smart ones or they will learn to ignore you. If you have done a little homework before you post your question here you will find almost everyone here eager to help you for as long as you can stand it. They just want to see you demonstrate a real interest, and that means you have already consulted some of the more obvious references. If you ask a question like how hard is a diamond you will get no respect because that information is easily available from a hundred sources. If you ask instead about directional hardness in diamonds or the hardness of isotropically pure diamonds, some of the smartest guys around will try and help you out and point you in the direction you want to go.

Paul,a fantastic Oberneisen specimen and a rare habit of course .. for me clearly a must have in the article. I hope to get the locality description ready soon.

Rock,here the Wolf mine stuff .. as always please 'polish' the english if needed B)-... now i have to pause adding for a few days, will be back next week.

Rhodochrosite from the Wolf mine is probably one of the best known mineral species from Germany in the world. The specimens from there are considered to be the best of Europe and they are present in museums and collections worldwide. Finds were restricted to the active mining period so nowadays specimens from there are highly sought after and increasing in value. The rhodochrosite varies in colour from salmon pinkish to raspberry pink or orange-reddish to brownish. Typically it is associated with limonitic matrix where it forms crystals and aggregates in vugs of the ore. The habit varies from single millet-seed shaped crystals to star or hedgehog shaped aggregates of those, barrel and cone shaped crystals as well as sheave-like aggregates. Most of the crystals are built by numerous small steep scalenohedral subindividues. The crystals reach up to about 2 cm size, larger crystals have been extremely rare. The majority of the crystallized samples show crystal sizes from a few mm to about 1 cm. Also botroydal and spherical aggregates and coatings were common. The aggregates often show a 'raspberry' like habit ('Himbeerspat' - raspberry spar - Breithaupt, 1832). The most beautiful specimens are of a deep orange-pink colour, they are translucent and provide a great contrast to the limonite matrix. Combo specimens of rhodochrosite with malachite-coated crystals of native copper (reaching sizes of up to about 3 cm) on matrix are the most interesting association of the Wolf mine. The best and richest specimens were found in a zone around the 350 m level.

The Wolf mine belongs to the Siegerland siderite district where mining goes back to celtic times. The ore of this district is primarily of sideritic type with more or less developed oxidation zones where limonite/goethite is prevalent. Also Pb, Zn, Cu and Ag as well as Co and Ni minerals occurred frequently - especially at the upper levels - and mostly have been mined at the beginning of modern mining. Mineralization is of hydrothermal origin and developed as veins in Devonian sedimentary rocks (shales, sand- and siltstone) of the Rheinisches Schiefergebirge. The Wolf mine was characterized by a deeply developed oxidation zone (to a depth of almost 400 m), probably due to the influence of the intrusion of tertiary basaltic melts in the neighborhood which provided thermal energy and fluid flow favouring the alteration of the siderite veins. The rhodochrosite finds were restricted to the limonitic ores of the oxidation zone. Towards depth the ore became sideritic with quartz gangue and towards the roots of the veins the quartz content increased.

The Wolf mine is one of the younger mines of the district. Mining started about 1870 when limonite ore was extracted via adits. In 1890 the Reifenrath brothers from Neunkirchen acquired the mine and sank a shaft. Having reached a depth of 300 m the mine was sold in 1917 to Krupp, Essen and modernized by the installation of new steam machines for haulage. The water pumps were fitted with electric power supply. Consequently the extraction tonnage increased to 4,000 - 5,000 tonnes per month. During the 1920s 200 to 250 miners worked at the mine. In 1925 the mining stopped due to economic reasons. The surface installations were demolished and the mine was flooded. 10 years later the reopening was prepared by pumping out the mine and the building of new surface installations including an electric hauling machine and a cableway to transport the ore to the central processing plant at the Füsseberg mine in Daaden-Biersorf. On 1st of may 1937 the mine was then reopened again. With an extraction of 84,000 tonnes of ore the year 1944 marks the best yield in the history of the mine. But in 1945 the mine closed again due to World War II impact and the mine was flooded again. In 1953/54 the last mining period at the Wolf mine started: it then was consolidated with the San Fernando, Friedrich-Wilhelm, Füsseberg and Große Burg mines to a combined mining complex. The mined ore was transported underground to the San Fernando mine and hauled and processed there. Finally in 1962 the mine was completely closed.

Jasen, that is an interesting rhodochrosite. Can you tell us something about where it comes from exactly, perhaps the geology of the locality and how many specimens like this have been found? The locality is a little vague and the specimen small and not well crystallized. It is sort of a marginal case and unless we had more information about it we probably would not include it.

I think that there were a number of different mines that produced rhodochrosite in Minnesota (Iron mines). Most are like these botyroidal masses, but there are small, pale pink crystals on manganese oxide matrix. They do show up from time to time in dealer stocks, but are of most interest to collectors specializing in rhodochrosite or Minnesota. Montreal mine pieces tend to be a bit better in size and quality (but rarer).

A major revision of the Rhodochrosite article has been completed. Take a look. I would like to thank all those who have made suggestions and contributions for improving the article. In most cases you will see your suggestions, images and written contributions reflected in the article. I would especially like to thank Roger Lang for the excellent information that he has thus far provided about the German rhodochrosite localities. Would that we had one like him for every country that produced specimens. Please feel free to chip in here with further suggestions.

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